M1.5.3 - Coefficient of friction

Use the coefficient of friction and the equilibrium condition F ≤ μR.

Use coefficient of friction to connect the rule to the data and decision in the question.

This matters because coefficient of friction determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply coefficient of friction to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: Coefficient of friction is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.